Effects of Growth Conditions on Carbon Utilization and Organic By‐Product Formation in <i>B. subtilis</i>

Abstract

Abstract The effects of growth rate and substrate concentration on cellular metabolism of glucose was studied with cultures of B. subtilis 168. Application of chemostat culture techniques allowed for the observation of each growth condition independent of the other. The relative flux of carbon through biosynthetic and non‐biosynthetic pathways was determined by monitoring cell density and distribution of extracellular side products in active cultures. A metabolic shift of glucose utilization pathways was observed in cell cultures grown at dilution rates greater than 0.36 hr −1 or with glucose feed levels exceeding 10 gll. The predominant side products detected by HPLC analysis were acetic acid, formic acid, lactic acid, and acetoin. The patterns of side product formation were analyzed in relation to the applied growth conditions.